What common mistakes should I avoid when winterizing my backyard pond?

Avoid common mistakes like leaving leaves to accumulate without netting, not storing pumps indoors, overfeeding koi late in season, and failing to maintain an ice-free hole for oxygen exchange. Also, avoid fully draining shallow ponds that expose fish to freezing. Skipping aeration or de-icer use can suffocate fish under ice. Proper planning and simple maintenance prevent these issues and ensure a healthy winter pond.